Methods of precisely forming bone tunnels in cruciate ligament reconstruction of the knee

ABSTRACT

A femoral guide for precisely positioning a guide wire on a bone surface of the femur includes a body having a lumen for receiving a guide wire and a tongue protruding from the body for engaging an edge or reference point on the bone surface with the tongue being spaced a predetermined distance from a longitudinal axis of the lumen. The lumen includes an opening allowing a guide wire extending through the lumen to contact the bone surface at a location spaced from the edge substantially the predetermined distance with the tongue engaging the edge. A stylus on the body can be driven into the bone to secure and stabilize the femoral guide prior to driving the guide wire into the bone through the lumen. With the guide wire driven into the bone, a bone tunnel can be formed substantially concentrically or coaxially along the guide wire such that a longitudinal axis of the bone tunnel will be disposed from the edge substantially the predetermined distance. Methods of precisely forming bone tunnels include the steps of engaging an edge of a bone surface with a tongue of the femoral guide, inserting a guide wire through a lumen of the femoral guide, driving the guide wire into the bone through the lumen and forming a bone tunnel in the bone along the guide wire such that a longitudinal axis of the bone tunnel will be disposed from the edge engaged by the tongue a distance substantially equal to the distance that the tongue is disposed from a longitudinal axis of the lumen.

This is a divisional of application(s) Ser. No. 07/839,466 filed on Feb.19, 1992, now U.S. Pat. No. 5,520,693.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to surgical instruments for preciselypositioning guide wires in bone allowing tunnels to be formed in thebone along the guide wires and, more particularly, to femoral guides forprecisely positioning guide wires in the femur in cruciate ligamentreconstruction of the knee allowing bone tunnels to be formed in thefemur along the guide wires at sites anatomically equivalent to thecruciate ligament and to methods of precisely forming bone tunnels.

2. Description of the Prior Art

Various surgical procedures utilize graft or prosthetic ligaments toreconstruct natural ligaments that have been damaged by injury ordisease. Where the ligaments to be reconstructed are found in joints orarticulations of the body, i.e., the connections of the various surfacesof the bones in the body, graft or prosthetic ligaments are typicallyimplanted and fixated in bones of the joint at sites anatomicallyequivalent to the natural ligament. In cruciate ligament reconstruction,such as anterior cruciate ligament reconstruction of the knee, tandem,isometrically positioned bone tunnels are formed, respectively, in thetibia and femur at sites anatomically equivalent to attachment of theanterior cruciate ligament, and a graft or prosthetic ligament havingbone blocks at its ends is inserted in the bone tunnels to extend acrossthe knee joint with the bone blocks disposed, respectively, in the bonetunnels. Interference bone fixation screws are inserted in the tibialand femoral bone tunnels to be positioned laterally between the boneblocks and walls of the bone tunnels to fixate the ligament and providea bone-tendon-bone graft. In anterior cruciate ligament reconstructionof the knee, it is very important that the bone tunnels be located atthe anatomic sites of attachment of the anterior cruciate ligament; and,where anterior cruciate ligament reconstruction is performed as an opensurgical procedure utilizing relatively long incisions on the order often inches in length to access the knee joint, the increased room formaneuverability afforded by the long incisions can enhance properplacement of the tibial and femoral bone tunnels. However, open surgerypossesses numerous disadvantages over closed, or least invasive surgery,including increased invasiveness and trauma, prolonged hospitalizationand rehabilitation times, increased patient discomfort, possibleviolation of capsular mechanoreceptors, dessication of articularcartilage and delayed post-surgical mobility. Accordingly, it ispreferred to perform anterior cruciate ligament reconstruction as aleast invasive, closed, or endoscopic, procedure wherein portals ofminimal size, such as are formed with a puncture or stab wound, intissue adjacent the knee are utilized to access the knee joint with theknee being visualized with an arthroscope, the portals being just largeenough to accommodate surgical instruments inserted at the knee joint.Arthroscopic anterior cruciate ligament reconstruction provides numerousbenefits over open surgery including minimal invasiveness and trauma,performance on an out-patient basis, reduced rehabilitation time,decreased patient discomfort, early, aggressive range of motion,cosmetically pleasing incisions, completion with tourniquet times underone hour, the opportunity to perform a diagnostic arthroscopy withouthaving to commit to anterior cruciate ligament reconstruction unlessconfirmed by the diagnostic findings and early weight bearing withoutloss of fixation.

Where cruciate ligament reconstruction is performed as a closed, orendoscopic, surgical procedure, the small size of the portals limitsaccess to and maneuverability at the knee joint making it relativelymore difficult to precisely place the tibial and femoral bone tunnels atsites anatomically equivalent to the cruciate ligament. In most cases,guide wires or pins are inserted through arthroscopic size portals fromexternally of the body and are driven, from externally of the body, inthe tibia and femur at desired locations for longitudinal axes, orcenters, of the tibial and femoral bone tunnels, allowing the bonetunnels to be formed along the guide wires, such as by drilling orreaming, substantially coaxially or concentrically with the guide wires.Although the guide wires are effective in guiding instruments, such asdrills and reamers, utilized to form the bone tunnels, problems canarise in arthroscopic cruciate ligament reconstruction in preciselypositioning or locating the guide wires. If the guide wires are notlocated and inserted at sites anatomically equivalent to attachment ofthe cruciate ligament, the tibial and femoral bone tunnels, as guided bythe guide wires, will not be properly located, and ligamentreconstruction will be impaired. In arthroscopic anterior cruciateligament reconstruction, it is difficult to position a guide wire on thefemur at a position corresponding to the anatomic center of attachmentof the anterior cruciate ligament. In order to position a tip of theguide wire on the femoral condyle at the anatomic center for theanterior cruciate ligament and drive the guide wire into the femur suchthat a bone tunnel formed along the guide wire will have a longitudinalaxis substantially aligned with the anatomic center of the anteriorcruciate ligament, the guide wire must be inserted through a tibial bonetunnel from a portal of minimal size, and a tip of the guide wire mustbe located on the femoral condyle with the guide wire held and driveninto the femur from externally of the knee. When positioning the tip ofthe guide wire on the femoral condyle, it is desired that the tip bepositioned high in a notch on the femoral condyle, the notch beingformed in a notchplasty procedure prior to formation of the bonetunnels, such that the longitudinal axis of the femoral bone tunnel willbe disposed sufficiently anterior, i.e., approximately 6-7 millimeters,to the posterior edge or “over-the-top ridge” of the notch and thefemoral bone tunnel will be as far posterior as possible while stillallowing a tunnel and not a trough with the cortical margin of the femurbeing neither too wide nor too narrow. However, it is extremelydifficult in arthroscopic anterior cruciate ligament reconstruction toposition and hold the guide wire from externally of the knee such thatthe tip of the guide wire is optimally, isometrically positioned on thefemur; and, even when properly positioned, the guide wire can slip orshift prior to being driven into the femur resulting in an improperlypositioned femoral bone tunnel and impaired placement of the graft orprosthetic ligament. Where instruments are used to help guide or holdthe guide wire, the instruments themselves can slip or shift causingdisplacement of the guide wire; and, frequently, the use of instrumentsdoes not eliminate the need for a surgeon to estimate where to placeinstruments such as drills or reamers when forming the femoral bonetunnel along the guide wire. Accordingly, arthroscopic anterior cruciateligament reconstruction as presently performed lacks instruments forprecisely positioning a guide wire on the femur at a site anatomicallyequivalent to the anterior cruciate ligament to allow a femoral bonetunnel formed substantially coaxially or concentrically along the guidewire to be optimally, isometrically positioned.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to overcomethe above-mentioned disadvantages of femoral guides and methods offorming bone tunnels.

Another object of the present invention is to provide a guide forprecisely positioning a guide wire on a bone surface in relation to areference edge on the bone surface engaged by the guide.

A further object of the present invention is to provide a femoral guidefor precisely positioning a guide wire in the femur such that a bonetunnel formed along the guide wire has a longitudinal axis substantiallyaligned with the anatomic center of attachment of the cruciate ligament.

It is also an object of the present invention to provide a guide havinga tongue for engaging an edge on a bone surface to position a guide wireinserted through the guide on the bone surface such that a longitudinalaxis of a tunnel formed substantially concentrically along the guidewire is a predetermined distance from the edge.

Yet another object of the present invention is to provide a femoralguide having a tongue and a lumen having a longitudinal axis disposed apredetermined distance from the tongue such that a guide wire insertedin the lumen has a longitudinal axis disposed substantially thepredetermined distance from the tongue.

A still further object of the present invention is to provide a femoralguide for precisely positioning a guide wire on the femur such that abone tunnel formed along the guide wire has a longitudinal axisapproximately 6-7 millimeters anterior to a posterior edge or“over-the-top ridge” of a notch on the femoral condyle.

An additional object of the present invention is to provide a guidehaving a stylus for being driven into the bone to stabilize the guideduring insertion of a guide wire into the bone along the guide.

Furthermore, it is an object of the present invention to provide amethod of precisely forming bone tunnels in a joint of the bodyendoscopically with a guide inserted at the joint from a portal ofminimal size to position a guide wire on a surface of a bone of thejoint such that the guide wire is a predetermined distance from areference edge on the bone surface engaged by the guide allowing theguide wire to be driven into the bone for forming a bone tunnel alongthe guide wire.

Another object of the present invention is to provide a method offorming bone tunnels in a bone of a joint of the body endoscopicallywith a guide inserted at the joint from a portal of minimal size andincluding positioning a tongue of the guide against an edge of a bonesurface of the bone such that a guide wire inserted through a lumen ofthe guide is positioned on the bone surface a distance from the edgethat is substantially equal to the distance from the tongue to alongitudinal axis of the lumen.

It is also an object of the present invention to provide a method offorming a femoral bone tunnel in arthroscopic cruciate ligamentreconstruction of the knee including the steps of inserting a femoralguide through a tibial bone tunnel from an arthroscopic size portal,positioning a tongue of the femoral guide against a posterior edge of asurface of the femoral condyle, inserting a guide wire through a lumenof the femoral guide to contact the surface of the femoral condyle anddriving the guide wire into the femur such that a bone tunnel formedsubstantially concentrically or coaxially along the guide wire has alongitudinal axis spaced from the reference edge a distancesubstantially equal to the distance from the tongue to a longitudinalaxis of the lumen.

Yet another object of the present invention is to provide a method ofarthroscopic anterior cruciate ligament reconstruction of the kneeincluding forming a closed or open end femoral bone tunnel in the femuralong a guide wire precisely positioned by a femoral guide insertedthrough a tibial bone tunnel from an anterolateral or anteromedialportal such that a longitudinal axis of the femoral bone tunnel isdisposed 6-7 millimeters anterior to a posterior edge or “over-the-topridge” of a notch on the femoral condyle.

Some of the advantages of the present invention are that accurate,isometric positioning of tibial and femoral bone tunnels in arthroscopiccruciate ligament reconstruction is enhanced, the time required toperform arthroscopic anterior cruciate ligament reconstruction isreduced, error in forming bone tunnels in arthroscopic cruciate ligamentreconstruction is minimized, femoral bone tunnels can readily be locatedhigh in a notch formed in the femur, the use of blind, or closed-end,femoral bone tunnels as well as open-end femoral bone tunnels inarthroscopic anterior cruciate ligament reconstruction is permitted, thecreation of a trough and not a tunnel when forming femoral bone tunnelsis avoided, a cortical margin that is neither too wide nor too narrow isinsured, tunnel placement can be verified prior to tunnel formation, thefemoral isometric point can be accurately identified, the need forsurgeons to estimate the position of drills and reamers when formingfemoral bone tunnels along guide wires is eliminated, anteromedial andanterolateral portals can be used for inserting guide wires inarthroscopic anterior cruciate ligament reconstruction, the size ofportals used in arthroscopic cruciate ligament reconstruction can beminimized, the femoral guide according to the present invention isstreamlined in structure, right and left knee compatible and can besterilized for repeated use, the tip of a guide wire positioned by thefemoral guide on a bone surface can be viewed endoscopically, afootprint can be created on a bone surface as guided by a guide wirepositioned by the femoral guide and examined prior to forming a bonetunnel allowing adjustments to be made if necessary, the femoral guideis designed to be accommodated in portals of very small size and theconfiguration of the femoral guide facilitates manipulation andmaneuverability at the knee joint as well as arthroscopic visualizationof the knee.

Accordingly, these and other objects and advantages are obtained withthe present invention as characterized in a femoral guide including anelongate body having a distal end, a proximal end and a longitudinallumen for receiving a guide wire and a handle mounting the proximal endof the body. The body includes a cylindrical member and a tip extendingangularly, distally from the cylindrical member. The lumen extendsthrough the cylindrical member from the proximal end toward the distalend, the lumen terminating distally at an opening on an arcuate surfaceof the tip, the opening being disposed proximally of the distal end. Thelumen has a diameter sized to closely receive the outer diameter of aguide wire inserted through the femoral guide such that a longitudinalaxis of the guide wire is substantially aligned with a longitudinal axisof the lumen, and the opening of the lumen allows the guide wire toprotrude distally from the body to contact a bone surface. The arcuatesurface of the tip terminates distally at an end wall at the distal end,and a tongue protrudes distally from the end wall and, therefore, thedistal end, of the body. The tongue has a surface for engaging areference edge on a surface of the bone, and the surface of the tongueis disposed a predetermined distance from the longitudinal axis of thelumen such that a guide wire inserted through the lumen will bepositioned in contact with the bone surface a distance from the edgethat is substantially equal to the predetermined distance. A stylusprotrudes from the end wall in the same direction as the tongue allowingthe stylus to be driven through the bone surface and into the bone withthe bone surface abutting the end wall and the tongue engaging thereference edge. The guide wire can be driven into the bone along thelumen, and the femoral guide can be removed from the guide wire allowingan instrument, such as a cannulated drill or reamer, to be mounted onthe guide wire with the guide wire extending through the cannulation todrill a tunnel in the bone substantially concentrically or coaxiallyalong the guide wire such that a longitudinal axis of the tunnel isdisposed from the reference edge substantially the predetermineddistance. A method of forming bone tunnels endoscopically, orarthroscopically, in joints of the body such as the knee includes thesteps of inserting the femoral guide at the joint through a portal ofminimal size, positioning a tongue of the femoral guide in engagementwith a reference edge on a surface of a bone of the joint, inserting aguide wire through a lumen of the femoral guide and contacting the bonesurface with the guide wire at a location spaced from the edge adistance substantially equal to the distance from the tongue to alongitudinal axis of the lumen, driving the guide wire into the bonethrough the lumen and forming a bone tunnel in the bone substantiallyconcentrically or coaxially along the guide wire.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a femoral guide according to the presentinvention.

FIG. 2 is a front view of the femoral guide of FIG. 1.

FIG. 3 is an enlarged, broken side view, partly in section, of thefemoral guide of FIG. 1.

FIG. 4 is a broken top view of the femoral guide of FIG. 1.

FIG. 5 is a perspective view of a knee showing the femoral guide of FIG.1 inserting a guide wire in the femur from an anteromedial portal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A femoral guide according to the present invention is shown at 10 inFIG. 1 and includes a body or probe 12 having a distal end 14, aproximal end 16 and a longitudinal axis and a handle 18 mounting theproximal end 16 of the body 12. The body 12 is preferably made ofstainless steel and includes an elongate, cylindrical member or tube 20terminating proximally at proximal end 16 and a tip 22 distally joinedto the cylindrical member 20, the cylindrical member 20 having alongitudinal axis coaxially aligned with the longitudinal axis of thebody 12. The tip 22 extends angularly, distally from the cylindricalmember 20 and includes an arcuate surface 24 extending distally from awall of the cylindrical member 20 with an inward curvature and anopposed arcuate surface 26 extending distally with an inward curvaturefrom a wall of the cylindrical member 20. The arcuate surface 24terminates distally at an end wall 28 at the distal end 14, the end wall28 having a planar surface disposed in a plane transverse andperpendicular to the longitudinal axis of the body 12 as shown in FIG.3. A tongue 30 protrudes or extends distally from the end wall 28 and,therefore, the distal end 14, in a direction parallel with thelongitudinal axis of the body 12, the tongue 30 terminating distally atan arcuate segment 32 as shown in FIG. 4. The tongue 30 is of generallyuniform width and thickness and has a planar surface 34 extendingperpendicularly from the end wall 28 to the arcuate segment 32 parallelwith and offset from the longitudinal axis of the body and an opposedplanar surface 36 joined to arcuate surface 26 and extending from thearcuate surface 26 to the arcuate segment 32 parallel with the uppersurface 34. A pair of opposing, parallel side walls 38 having planarsurfaces laterally, equidistantly disposed with the longitudinal axis ofthe body 12 join the arcuate surfaces 24 and 26, the end wall 28 and thetongue 30 with the side walls 38 merging with the cylindrical wall ofthe body 12 as shown in FIGS. 3 and 4. A longitudinal passage or lumen40 extends through the body 12, the lumen 40 having a diameter sized toclosely receive the outer diameter of a guide wire or pin 41 as shown inFIG. 3 and as will be explained in greater detail below, and alongitudinal axis coaxially aligned with the longitudinal axis of thebody 12 such that the longitudinal axis of the lumen is spaced from theupper surface 34 of the tongue 30 by a predetermined distance. The lumen40 includes a first diameter section 42 in cylindrical member 20extending from the proximal end 16 in a distal direction and a second,relatively larger diameter section 44 coaxially aligned with the firstdiameter section 42 and distally joined to the first diameter section 42within the cylindrical member 20 at an internal, annular shoulder 46,the second diameter section 44 extending distally from the shoulder 46through the tip 22 to an opening 48 on the arcuate surface 24 that isgenerally oval or elliptical in configuration when viewed from above asshown in FIG. 4 with the opening 48 being disposed proximally of the endwall 28 and, therefore, the distal end 14. A stylus 50 having a sharppoint or tip 52 protrudes distally from the end wall 28 in the samedirection as the tongue 30, the stylus 50 having a generally conicalconfiguration with the point 52 at the apex of the conical stylus and anaxis of the stylus through the apex being parallel with the uppersurface 34 of the tongue 30 such that the stylus can be driven into bonewith the end wall 28 abutting a surface of the bone and an edge of thebone surface engaged by the upper surface 34 of the tongue 30 as will beexplained further below.

The body 12 can be of integral, unitary construction, or the body 12 canbe formed of multiple pieces joined at junctions, such as shown byjunction 54 in FIG. 4, by techniques such as welding. Where the body isformed of multiple parts or pieces, it is preferred that the junction 54be disposed at least 0.250 inches proximally of the shoulder 46. The tip22 can be formed as a single piece of unitary, integral construction orthe tip 22 can be formed of multiple pieces joined by techniques such aswelding allowing the stylus 50 and the tongue 30 to be formed separatelyfrom the body 12. The body 12 can have various configurations andarrangements of parts providing a lumen sized to closely receive theouter diameter of a guide wire or pin and a tongue protruding distallyfrom the body and having a surface for engaging an edge of a bonesurface to position a longitudinal axis of a guide wire received in thelumen on the bone surface a distance from the edge that is substantiallyequal to the distance from the surface of the tongue to the longitudinalaxis of the lumen. Accordingly, it will be appreciated that the lumen 40need not be coaxially aligned with the body 12, and that thelongitudinal axis of the lumen 40 can be offset from the longitudinalaxis of the body 12. Depending on the configuration of the bone surfaceand the edge of the bone surface to be engaged by the tongue, the uppersurface of the tongue need not be parallel to the longitudinal axis ofthe lumen and the end wall need not be perpendicular thereto.Accordingly, it will be appreciated that the tongue and end wall canhave various configurations and that the tongue can be angled andnon-parallel to the end wall and the longitudinal axis of the lumen. Thestylus 50 can have various configurations and can be assembled on thebody 12 at various locations to allow the stylus to be driven into bonewith an edge of a bone surface engaged by the tongue 30 to secure andstabilize the femoral guide prior to inserting a guide wire through thelumen and when driving the guide wire into bone. According to apreferred embodiment of the femoral guide 10, the diameter of the firstdiameter section 42 is substantially 0.099 inches to receive a guidewire or pin having an outer diameter of 0.0985 inches, the distance fromthe upper surface 34 to the longitudinal axis of the lumen 40 issubstantially 0.276 inches such that a bone tunnel formed substantiallyconcentrically or coaxially along a guide wire positioned through thelumen of the femoral guide will have a longitudinal axis disposed 6-7millimeters from the edge of the bone surface engaged by the tongue 30.The length of tongue 30 from end wall 28 to arcuate segment 32 issubstantially 0.375 inches, the length of stylus 50 from end wall 28 topoint 52 is substantially 0.155 inches, the radius of curvature forarcuate surface 24 measured from a point 3.00 inches from the lowersurface 36 and 0.23 inches proximally from arcuate segment 32 looking atFIG. 3 is substantially 2.78 inches, the radius of curvature for arcuatesegment 26 measured from a point 2.40 inches from the lower surface 36and 1.56 inches proximally from the arcuate segment 32 looking at FIG. 3is substantially 2.65 inches, the outer diameter of cylindrical member20 is substantially 0.190 inches, the distance between the side walls 38is substantially 0.150 inches and the overall length of the body 12 fromarcuate segment 32 to the proximal end 16 is substantially 6.00 inches.It will be appreciated that the dimensions of the femoral guide candepart from those described here as illustrative and that the femoralguide 10 can have various dimensions and configurations allowing thefemoral guide to be inserted through portals of minimal size and to bemanipulated within close confines of joints in the body.

The handle 18 is preferably made of stainless steel and includes amounting section 54 having a longitudinal, cylindrical passage 55therein with a diameter sized to closely receive the outer diameter ofthe cylindrical member 20 of body 12 and a gripping section 58 extendingangularly outwardly from the mounting section 54. The mounting section54 has a pair of opposing side walls 60 defining a width that tapers inthe direction of the cylindrical passage 55 as shown in FIG. 2 and apair of curved forward and rearward walls 62 and 64, respectively,joining the side walls 60 as shown in FIG. 1. As shown in FIG. 1, theforward and rearward walls 62 and 64 curve toward each other such thatthe length of the handle tapers from near the cylindrical passage 55 tothe gripping section 58. The gripping section 58 includes a pair of sidewalls 66 joined to the side wall 60 and terminating at a radial wall 68as shown in FIG. 2, and forward and rearward walls 70 and 72,respectively, joining the side walls 66 as shown in FIG. 1. The forwardand rearward walls 70 and 72 are joined, respectively, to the forwardand rearward walls 62 and 64 of the mounting section 54. Ridges 74 areprovided on the rearward wall 72 of the gripping section 58, the ridges74 extending transverse to the side walls 66 to facilitate grasping ofthe handle 18 during use. Indicia can be provided on the side walls 60of the mounting section or at any other suitable location on the handle18 to identify the distance from the upper surface 34 of tongue 30 tothe longitudinal axis of the lumen 40. The cylindrical member 20 of thebody 12 is concentrically mounted in the passage 55 of the handle 18with the proximal end 16 of the body 12 extending proximally of themounting section 54 a short distance and, preferably, 0.375 inches, asshown in FIG. 1., and the gripping section 58 is disposed diametricallyopposite the tongue 30. The body 12 can be secured to handle 18 bytechniques such as welding allowing the femoral guide 10 to besterilized for repeated use utilizing known sterilization procedures.With the body 12 assembled with the handle 18, the gripping section 58extends angularly, distally in a direction outwardly from thelongitudinal axis of the body 12 such that the handle section 58 isdisposed at an acute angle with the longitudinal axis of the body 12 forengagement in an inverted position. It will be appreciated that thehandle 18 can have various structural configurations to mount the body12 and provide a gripping section permitting the femoral guide 10 to begrasped and held conveniently, from externally of the body, and toposition the tip 22 in the body via a portal of minimal size.

According to a method of operation for the guide 10 in precisely formingbone tunnels in a bone of a joint endoscopically, the femoral guide 10is inserted at a joint in the body through a portal of minimal sizeformed in tissue adjacent the joint with the joint being visualizedendoscopically. With the handle 18 manually grasped and held in aninverted position externally of the body, the tip 22 is manipulated toposition the upper surface 34 of the tongue 30 against an edge of a bonesurface that is to have a tunnel entry thereon. With the edge of thebone surface abutting the upper surface 34 of the tongue 30, thelongitudinal axis of the lumen 40 will be spaced from the edge adistance that is equal to the distance from the upper surface 34 to thelongitudinal axis of the lumen 40. The guide 10 is then driven towardthe bone surface such that the sharp point 52 of the stylus 50 entersthe bone surface and secures and stabilizes the femoral guide. A guidewire or pin, such as guide wire 41 shown in FIG. 3, is inserted in thelumen 40 from the proximal end 16 of the guide 10 externally of thebody. The guide wire 41 will exit the lumen 40 through the opening 48and, by moving the guide wire 41 toward the bone surface, a tip of theguide wire 41 will contact the bone surface at a point that is spacedfrom the edge a distance substantially equal to the distance from theupper surface 34 to the longitudinal axis of the lumen 40. The curvatureof the arcuate surface 24 allows the tip of the guide wire 41 to be seenendoscopically. An end of the guide wire 41 protruding from the proximalend 16 is coupled, externally of the body, with a tool or instrument fordrilling the guide wire in bone, and the guide wire is drilled a desireddepth into the bone. The guide 10 is then removed from the guide wirethrough the portal and a tunneling instrument, such as a drill orreamer, having a central cannulation is mounted on the guide wire 41externally of the body with the guide wire extending through thecannulation. The tunneling instrument is inserted at the joint throughthe portal and, with the instrument guided by the guide wire 41, a bonetunnel is formed substantially concentrically or coaxially along theguide wire 41 in the bone to a desired depth such that a longitudinalaxis of the bone tunnel is located from the edge a distancesubstantially equal to the distance from the upper surface 34 to thelongitudinal axis of the lumen 40. Accordingly, the guide 10 accordingto the present invention allows bone tunnels to be formed in bone alongguide wires with entry points of the bone tunnels located on surfaces ofthe bone by positioning the guide wires with the guide at the centers ofthe tunnel entry points such that the tunnel entry points are preciselylocated on the bone surfaces in relation to reference points or edges onthe bone surfaces that can be engaged by the tongue of the guide.

The femoral guide 10 according to the present invention is useful invarious diverse types of surgical procedures involving the need toprecisely position and form bone tunnels in bone endoscopically and, inparticular, the femoral guide 10 is useful in ligament reconstruction injoints of the body and, especially, the knee. The femoral guide 10 canbe used in reconstructing various diverse types of ligaments and, whenused to reconstruct ligaments of the knee, the femoral guide 10 isparticularly useful in forming bone tunnels arthroscopically whenreconstructing the anterior cruciate ligament of the knee. According toa method of arthroscopic anterior cruciate ligament reconstruction ofthe knee, a portal of minimal size is formed in tissue adjacent the kneeto access the knee joint with the knee being visualized with anarthroscope. A diagnostic arthroscopy can be performed prior to anteriorcruciate ligament reconstruction without having to commit to an anteriorcruciate ligament reconstruction unless confirmed by the arthroscopicfindings. The portal should be placed anteromedial or anterolateral onthe knee and, preferably, the portal is placed medially on the knee as aportal placed too high can result in too steep an angle for the tibialbone tunnel while a portal placed too low can interfere with themeniscus. The portal should be placed just superior to the medialmeniscus and must not penetrate any portion of the patellar tendon.Instruments are inserted through the portal to perform any necessaryprocedures such as meniscectomy, minuscal repair, removal of loosebodies, and debridement of anterior cruciate ligament tears. Aninstrument is inserted through the portal to perform a notchplastyresulting in a notch 76, as shown in FIG. 5, on the femoral condyle, thenotch 76 being approximately 2 centimeters in width and adequatelyposterior to include the extreme posterolateral femoral cortex andhaving a surface 77 terminating at a posterior edge or “over-the-top”ridge 78. Where an autogenous graft ligament is utilized, a graft havingbone blocks at its ends is harvested from the patellar tendon throughvertical incisions, i.e., an anteromedial incision or portal beginning 1centimeter medial to the tibial tubercle and 2 centimeters distally tothe joint line and being 2.5 centimeters in length and a patellarincision 2.5 centimeters in length and beginning at the distal pole ofthe patella and extending proximal over the midline of the patella. Aguide wire or pin is placed at the anatomic center of the tibial tunnelentry on the tibia via an anterolateral portal or the anteromedialportal 80 previously used to harvest the graft. An instrument such as adrill or reamer having a cannulation is mounted on the guide wire withthe guide wire extending through the cannulation, and a tunnel 82 isdrilled in the tibia substantially concentrically or coaxially along theguide wire at a site anatomically equivalent to the anterior cruciateligament. The drill or reamer and the guide wire are removed from thetibia and, with the knee at an angle of 30 to 45′, the femoral guide 10is introduced through the tibial bone tunnel 82 from the anteromedial oranterolateral portal 80, and the femoral guide 10 is advanced across theknee joint with the handle 18 held externally of the body. The tongue 30of the femoral guide 10 is positioned against the posterior edge orridge 78 and, once positioned, the femoral guide 10 is moved toward thesurface 77 to drive the stylus 50 through the surface 77 and into thefemur thusly securing or stabilizing the femoral guide 10. A guide wire41 is inserted through the lumen of the femoral guide from externally ofthe body such that a tip of the guide wire protruding through theopening 48 contacts the surface 77 to establish a longitudinal axis orcenter for an entry point of a tunnel to be formed in the femur alongthe guide wire 41, the arcuate surface 24 allowing the tip of the guidewire 41 to be seen arthroscopically. A desired position for the femoralbone tunnel is high in the notch 76 with a longitudinal axis or centerof the femoral bone tunnel located approximately 6-7 millimetersanterior to the edge or ridge 78, and the distance from the uppersurface 34 of the tongue 30 to the longitudinal axis of the lumen 40results in the guide wire 41 being placed at the desired position on thesurface 77. An end of the guide wire 41 protruding from the proximal end16 of the femoral guide 10 is coupled with an instrument for drillingthe guide wire 41 in bone, and the guide wire 41 is drilled into thefemur as shown in FIG. 5. The guide wire is drilled into the femur adepth of approximately 3-4 centimeters for a blind, or closed end,femoral bone tunnel and, for an open end femoral bone tunnel, the guidewire 41 is drilled into the femur until it exits the lateral femoralcortex but not through the skin. The femoral guide 10 is backed out ofthe femur and removed from the knee through the portal 80, and aninstrument for forming a bone tunnel, such as a drill or reamer, havinga cannulation therein is mounted on the guide wire 41 with the guidewire extending through the cannulation. The drill or reamer is insertedthrough the portal 80 along the guide wire, and a footprint of the drillor reamer is created on the surface 77 and examined arthroscopically toinsure accurate positioning of the femoral bone tunnel entry point. Thewidth of the posterior cortex remaining should be approximately 1-2millimeters, the posterolateral femoral cortex must be adequatelyidentified and the femoral bone tunnel should be as far posterior aspossible while still allowing a tunnel and not a trough. If the corticalmargin is too wide or too narrow, the guide wire 41 may be reinsertedand another footprint made and examined until accurate placement of thebone tunnel is confirmed. Once the entry point for the femoral bonetunnel has been properly placed, the femoral bone tunnel is drilledalong the guide wire and, for a blind tunnel, the tunnel is drilledslightly deeper than the length of the bone block intended for fixationin the femoral bone tunnel and, for an open tunnel, the tunnel isdrilled through the lateral femoral cortex. The drill or reamer and theguide wire 41 are removed through the portal 80, and the autogenousligament or a prosthetic ligament is inserted through the tibial bonetunnel and across the knee joint with a bone block disposed in each ofthe bone tunnels. Interference bone fixation screws are then inserted inthe tibial and femoral bone tunnels laterally between the bone blocksand walls of the bone tunnels in directions parallel with longitudinalaxes of the bone tunnels to fixate the ligament.

Accordingly, the femoral guide and methods of forming bone tunnelsendoscopically according to the present invention allow bone tunnels tobe precisely formed endoscopically in bone along guide wires bypositioning the guide wires such that longitudinal axes of the bonetunnels formed substantially concentrically or coaxially along the guidewires are spaced from reference edges on the bone a predetermineddistance. The femoral guide of the present invention allows femoral bonetunnels to be precisely positioned in arthroscopic cruciate ligamentreconstruction at sites anatomically equivalent to the cruciate ligamentto insure accurate graft or prosthetic ligament placement andisometricity. The femoral guide permits the use of small size portals inarthroscopic cruciate ligament reconstruction and is designed tofacilitate manipulation and maneuverability at the knee joint. Thefemoral guide facilitates arthroscopic viewing of the tip of the guidewire on the femoral condyle and examination of the footprint createdprior to forming the femoral bone tunnel. The femoral guide and themethods of forming bone tunnels according to the present invention allowguide wires to be inserted at the knee from anterolateral andanteromedial portals and reduce the number of portals required inarthroscopic cruciate ligament reconstruction of the knee. By preciselypositioning a guide wire a predetermined distance from an edge on a bonesurface, the femoral guide and methods of forming bone tunnels accordingto the present invention avoid errors in placing bone tunnels andeliminate the need for surgeons to estimate where to put instruments,such as drills or reamers, when forming bone tunnels. The tongue of thefemoral guide according to the present invention allows an edge, a ridgeor some other structure of bone to be used as a reference in formingbone tunnels such that longitudinal axes of bone tunnels formed alongguide wires positioned via the femoral guide will be located apredetermined distance from the reference. The stylus of the femoralguide enhances accuracy and precision in forming bone tunnels bysecuring or stabilizing the femoral guide relative to the bone prior todrilling the guide wire.

Inasmuch as the present invention is subject to many variations,modifications and changes in detail, it is intended that all subjectmatter discussed above or shown in the accompanying drawings beinterpreted as illustrative only and not be taken in a limiting sense.

1. A method of locating the proper position for drilling a tunnel forendosteal fixation of a graft between a first bone and a second bone,said method comprising the steps of: drilling a tunnel through saidfirst bone; inserting a cannulated drill guide comprising a cannulatedshaft having an offset hook located on a distal end thereof through saidtunnel and engaging a notch in said second bone with said offset hook,said shaft being cannulated along its entire length and having acentrally located longitudinal axis, said offset hook being offset fromsaid longitudinal axis of said cannulated shaft for aligning the drillguide at a predetermined offset location in the notch; and drilling atunnel into said second bone at the predetermined offset location.
 2. Amethod according to claim 1, wherein said first bone comprises a tibiaand said second bone comprises a femur.